1. Field of the Invention
The present invention relates to a method and apparatus for communication of audio and video information in digital form over a network.
2. Background Art
The internet can be used to transmit video and audio data. Typically this is accomplished by connecting a video camera and microphone to a computer system. The video and audio data is converted to a form that can be transmitted over a network. The computer system is used to make a connection to the internet, and the video and audio data is transmitted onto the internet. A disadvantage of the prior art schemes is the necessity to use a computer system to couple the input devices (camera, microphone) to the internet.
A number of cameras are sold as being particularly suited for connection to a computer system. For example, the "QuickCam" by Connectix is used to capture still and video images that can be manipulated by a computers system. Another product is the "Network Eye" from MicroPlex. Among the disadvantages of prior art camera systems is an inability to operate at a full video frame rate, inability to emit RTP Internet standard protocol streams, lack of support for the use of multicast data transport, and lack of audio.
Prior art camera functionality is accomplished by one or more add-in cards and a personal computer or workstation. This is necessary because hardware is needed for codecs and compression functions and a complete, TCP/IP-network-enabled computer is needed to run the protocols needed for the device to communicate data on the Internet.
A camera from Active Imaging, intended for use in security video applications, uses the MPEG video compression standard and purports to not require a computer system to operate on a network. This camera does not function well in unreliable environments (such as Local Area Networks), and it does not lend itself to multicast transmission. It also involves the use of costly encoding hardware.